Phonograph attachment



Nov. 22, 1927. 1,650,089

D. H. Moss l 65 INVENTOR. J JcwzdH/Vass,

9 v t ATTORNEY Patented Nov. 22, 1927.

UNlTED STATES PATENT OFFICE,

DAVID MOSS, OF NEWARK, NEW JERSEY, ASSIGNOR TO BRANDES LABORATORIES,INC., OF NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

PHONOGRAPH ATTACHMENT.

Application filed January a simp e device which may be connected in theoutput circuit of any radio receiver and connected with the tone arm ofa phonograph for utilization of the sound amplifying horn of thephonograph as a reproducer ot' the received signaling energy Anotherobject of my invention is to provide a construction of phonographattachment for the reproduction of radio concerts,

lectures, news, music and other entertainment in which anelectromagnetic sound reproducing mechanism may be adjusted with respectto the sound reproducing diaphragm to a. point of desired amplitude andtone quality, with means for limiting the movementot' theelectromagnetic sound reproducing mechanism in the-direction of thesound reproducing diaphragm for preventing undue'strain being placedupon the sound reproducing diaphragm by abutment of the soundreproducing magnets with the surface of the diaphragm. I p

Still another object of my invention is to provide a construction ofcasing for a 110- nograph attachment where a portion 0 the casing isinstruck to cooperate with an adjustable leversecured to theelectromagnetic driving mechanism for limiting the move- .ment of theelectromagnetic driving mechanism with respect to the sound reproducingdiaphragm for preventing, abutment of the electromagnets with thediaphragm.

A further object of myinvention is to provide a mounting for anelectromagnetic driving mechanism in which the electromagnetic polepieces are carried upon a screw threaded plate member which may berotatably adjusted within a casing which sup ports the soundreproducing" diaphragm with means for actuating the electromagneticdriver from a point exterior to the casing for varying the distancebetween the electromagnetsjand the sound reproducing diaphragm from aminimum determined a limiting stop between the electromagnetic driverand a projection from one wall of the 8, 1926. Serial No. 80,120.

phonograph attachment casingto a maximum which is substantially 360 inthe re-,

verse direction from the limiting position My invention will be moreclearly understood from the specification hereinafter following byreference to the accompanying drawings, wherein: y

Figure 1 is a partial perspective view showing the relative position ofa ph0nograph attachment construction in accordance with my inventionmounted upon a phonograph; Fig. 2 is an end view of the phonographattachment casing; Fig. 3 is a plan view showing the phonographattachment casing and a connecting nozzle which interconnects the tonearm ofa phonograph with the phonograph attachment casing; Fig. 4 1s across-sectional view through the phonograph attachment casing showingthe interior working parts in front elevation;

and Fig. 5 is a cross-sectional view through the phonograph attachmenton line 5-5 of Fig. 4.

Referring to the drawings in detail, the phonograph attachment has beenillustrated as having a. casing-'1 with an extended cy lindrical portion2 forming a sound delivery orifice forthe attachment. An end wall of thecasing'l is provided on its interior with an annular pro eeting ringmember 3 forming a support for a sound reproducing diaphragm which isgripped upon its opposite side bya screw-. threaded ring member 5 havingan annular projectin ring portion 6 which grips the surface ot thesoundreproducing diaphragm. The casing l is threaded interiorly asrepresented at 7 to re ceive a screw threaded plate member 11 having ascrew threaded portion 9 which is engaged with the screw threads 7 for'adjust- J ably positioning the electromagnet 7 with respect to the diahragm 4. The periphery of the plate mem er 11 is toothed as representedat 10 in order to provide for an adjustment of theelectromagneticdriving as mechanism'from the exterior of the casing Agasket member 8 is positioned between the upper surface of the screwthreaded portion 9 and the screw threaded ring member. 5 enabling theelcctromagnet 12 to be adjusted with respect to the sound reproducingdla phrsgm and all of the parts locked in posi- 'tion againstmechanicalvibration and r: r? tling. In the center of the plate memberI: I provide a projecting screw member 14 su? rounded by a centralserrated portion 16 around which a lever member 15 may be adjusted. Thelever member 15 projects radiall from the central screw member 14 and 1Sbent atrightangles as represented at 17 to present an end portion 18which clears the binding posts 33 which connect with the bobbins 12. Thelever member 15 may be adjusted in any desired angular position and setin such position by tightening the screw member-14. Casing 1 is providedwith an extension which forms a bearing for a shaft member 31 whichprojects' outside of the closure of the phonograph attachment. The shaftmember 31 carries a pinion 32 which meshes with the toothed periphery 10of the plate 11 enabling the plate 11 to be. adjusted in the screwthreads Z of easing 1 to presentthe magnets 12 at a desired positionwith respect to diaphragm 4. The shaft 31 projects outside of thephonograph attachment casing and is operated by a knob member 34. Thecasing comprises a curved wall 24 terminating in portions 22 and 23 andprovided with a bottom closure portion 20. The rear wall 25 entirelyencloses the electroma netic drivin mechanism carried bv casing 1 andhas an outlet therein throu h whichthe flexible conductors 36 pass to te output terminals of the electron tube amplifier of the radio receiver.The bottom wall 12!) of the phonograph attachment casing is instruck asrepresented at 19 leavin a gap 23 therein and providing an obstructionmember for path of movement of the end 18 of the'radial adjustable lever15. The instruck portion 19 extends vertically upwardv and forms anabutment for the end 18 0f the lever 15 when the knob 34 is rotated tomove the plate member 11 to a position where the pole pieces of themagnet bobbins 12 tend to abut with the surface of diaphragm 4;Thisifconstruetion provides a' limiting stop feature for the electromanetic driver to prevent excessive strain fromdieing placed uponthefdiaphragm 4 by continued movement of .the magnet bobbins 12thereagainst. A magnetic reluctance gap is formed between theen'ds ofthe ole pieces of the magnet bobbins 12 and the igiphragm 4 for securinga desired operation of the phonograph attachment and the screw mem-'ser. 14 then adjusted to position the lever 15 in abutment with theupwardly extending lug member 19 preventing a further decrease in themagnetic reluctance gap. With this settingofthe device by factoryinspection the attachment is capable of adjustment through an angularmovement of substantially 360 upon rotation of knobl34 to se cure adesired operation of the attachment with respectto amplitude and tonequality foria given characteristic of the incpming signaling energy. Theseat' portions 22 and 23 permit the attachment to be'mountedconveniently adjacent the record table of a phonograph as illustrated inFi 1 where the tone arm 27 of the phonogra h 28 is con nected through alink 26 with the sound delivery orifice 2 of the casin 1 and connectionestablished b means 9 the rubber nozzle 25. The attae ment is mountedadjacent the record table 29 of the'phonograph and no modification isnecessary with the exception of the removal of the phonogra h sound boxfrom the'tone arm and the'su stitution of the conneetor 25'thereon i Theconstruction of the phonograph at-. tachment is substantially foolpr'oof by reason of the limiting stop adjustment 'which I provide whichprevents careless operation of the adjustable knob 34 and the ultimatedestruction or the sound r'eprodueing diaphragm. The adjustable magneticreluctance gap atl'ords means for securing a high degree of efficiencyin the reception of signa ing energy of differing characteristics. WhileI have described the attachment in certain specific embodiments, Idesire that it be understood that. modifications may be made and that nolimitations upon the invention are intended other than-those imposed bythe scope of the appended claims.

What I claim and desire to secure by Let- {ers Patent of the .UnitedStates isas folows:

1. A phonograph attachment com rising in combination an electromagneticriving mechanism, a easing into which said mechanism may be screwthreaded, adiaphragm carried in said casing, a. closure covering therear of said casingandznga ing the sides thereof, means passing t 'fougsardjclosure for controlling the rotation {of said drivingmechanism'w-ithin said casing for jrefiecting an adjustment of saiddriving mechanism with respect to saidsound reproducing diaphragm, andmeans projecting from one side of said closure adjacent the rear-of saidelectromagnetic driving mechanism for preventing decrease in themagnetita f reluctauce gap, between said electromagnetic driving lltmechanism and said diaphragm beyond a selected limiting distance.

2. A phonograph attachment comprisin In combination an interiorly screwthreade casing, a sound delivery orifice extending from one sidethereof, a sound-reproducing diaphragm carried within said casing, aplate member screw threaded within-said casing, an electromagneticdriving mechanism carried by said plate-member and adjusted with respectto said diaphragm for varying the magnetic reluctance gaptherebetween, aclosure arranged to be telescoped over said casing and substantiallyconformmg with the shape thereof, rotary means for imparting rotarymovement to said plate member, an integral ton ue' projecting from theinner walls oi saidv cv .0 1 16 and a cooperdiaphragm carried withinsaid casing, a

plate member screw threaded within said casing, teeth formed-on theperiphery of said plate member, an electromagnetic dllV! ing mechanismcarried by said plate member, a shaft member journaled in said casingand having a pinion thereon for en age ment with the teeth on'theperiphery 0 said plate, a closure telescoped upon said" casing andsubstantially confor with the shape thereof, said shaft memberprojecting through said closure and rotatable from the exterior thereofWithin predetermined limits for varying the magnetic reluctance gapbetween said electromagnetic driving mechanism and said -dia hragm.

4. A phonograph attachment comprising in combination an interiorl yscrewthreaded casing, a sound: delivery orifice extending from one sidethereof, a sound reproducing diaphragm carried within said casing, a-

plate member screw threaded within said casing, a lever member mountedupon a stud centrally projecting from one side of i said plate member,an elechomagnetic driving mechanism carried by the opposite side of saidplate member, a closure telescoped over said casin a rotatable shaftmember journaled in sai casing and passing through said closure foradjusting the position of said plate member insaid casing, said closurehaving an instruck projection forming an abutment with the end of saidlever memher for providing a limiting stop to the movement of saidelectromagnetic driving mechanism beyond a selected magnetic reluctanceap.

5. A p onograph attachment comprising in combination an interiorly screwthreade casing, a sound delivery orifice extending from one side of saidcasing, a sound reproducing. diaphragm positioned within said casing,- aplate member screw threaded within said casing andcarryingelectromagnetic drivi mechanism for actuating said sound repro ucingdiaphragm, a lever member mounted upon the stud rojec from the rear ofsaid plate mem r, a su stantially trian shaped casing telescopicallyposition upon said first mentioned casing, said trian 'ular shapedcasing providing a support or said first mentioned casing and havmg aninwardly projecting lug member therein arranged to form an abutment forthe end of said lever member for providin a limiting stop to themovement of sai electromagnetic driving mechanism beyond a predeterminedposition ior fixing the mini: mum and maximum magnetic gap to which saiddriving mechanism maybe adjusted with respect to said sound reproducingdiaphragm. i f

In testimony whereof I afiix my signature.

DAVID H. MOSS.

